Wire gun



Oct. 7, 1969 A. J. GRANDY 3,470,861

- WIRE sun Filed March 15, 1962 2 Sheets-Sheet 1 HI: m

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INVENTOR. ANDREW J. GRANDY ATTORNEYS= Oct. 7, 1969 A. J. GRANDY 3,470,861

WIRE GUN Filed March 15, 1962 2 Sheets-Sheet l2 8 9 E? U. m 2 LL.

I INVENTOR. ANDREW J. GRANDY BY 7 QM/ a 39247 ATTORNEYS United States Patent 3,470,861 WIRE GUN. Andrew J. Grandy, 2707 Grant Ave., North Hills, Pa; 19038 Filed Mar. 15, 1962, Ser. No. 180,058 Int. Cl. F4111 7/02; F16f 7/00 US. Cl. 124-18 8 Claims The invention described herein may be manufactured and used by or for the Government for govermental purposes without the payment to me of any royalty thereon.

This invention relates to a hand held wire gun for loading and projecting or rapidly extending a captive length of spring wire over a considerable distance under the impetus of internal torsional stresses in the wire, and has for an object to provide a simplified means for accomplishing this result. In accordance with the invention a gun of this type may be provided for quickly laying a wire entanglement, or a communication wire over fiat ground, or for throwing a wire across a chasm or stream preparatory to erecting a bridge, and for a multitude of uses.

FIG. 1 shows a use for a device embodying the invention to shoot a wire across a chasm for communication uses, or preparatory to erecting a bridge.

FIG. 2 is a longitudinal view in cross-section of a wire gun device representing one embodiment of thi invention.

FIG. 3 is a rear end view of the device of FIG. 2.

FIG. 4 illustrates a short length of untwisted wire having barbs formed along at least one edge thereof in accordance with the invention.

FIG. 5 schematically shows one system for making a supply reel of twisted wire for purposes of the invention.

FIG. 6 shows a short length of twisted wire from which internal stress has been removed in accordance with the invention.

FIG. 7 schematically shows a system for winding Wire flatwise in a unit to provide internal stress for its intended use in accordance with the invention.

FIG. 8 is a fragmentary end view, in perspective, of a collapsible mandrel element for use in the system of FIG. 7.

Referring to the drawings, a length of wire as indicated in FIG. 1, is shot from a gun of the type shown in FIGS. 2 and 3, under the impetus of internal torsional stress within the wire which is processed and wound flatwise to contain such internal stress.

This is accomplished by taking a supply reel 10 of soft untempered spring steel wire preferably of rectangular cross section and free of internal torsional stress as shown in FIG. 5. This wire should be of about a 1050 to 1095 carbon content and capable of being heat treated and quenched in a manner well known in the art to have a Rockwell C hardness of about 38 to 45 with its elastic limit and ultimate strength greatly increased. Two guide rolls 11 and 12 feed the untwisted soft spring wire between them from the reel 10 as indicated, and function to prevent any later applied twist in the wire from feeding back to the reel 10. Two more guide rolls 13 and 14 are preferably spaced from the rolls 11 and 12 along the wire the pitch distance of a twist and the rolls 13 and 14 are rotated around the wire in the plane of their axes at a rate depending on the speed of the wire to provide a uniform twist therein as indicated at 16. This rotation may be by hand but preferably by mechanism (not shown) geared to the drive for the Wire from the rolls 11 and 12. The degree of twist is preferably at a rate to impose a torsional twist upon the wire which is well above its elastic limit thereby leaving a permanent set of the soft wire.

The rectangle 15 may be taken to represent an appro- 3,470,861 Patented Oct. 7, 1969 priate heater through which the wire is passed and following which it is promptly quenced to harden it and raise its elastic limit and ultimate strength far above what it was previously in its .untempered condition. Conventional heat treatment of this type is familiar to those skilled in the art. Any remaining torsional stress as produced in the wire at 16 from the rolls 13 and 14, is thus removed by the heating and tempering. After this heat treatment the twisted but torsionally unstressed wire as at 17 is wound up on a storage reel 18.

The twisted wire 17 is unsuitable for use in the wire gun of FIG. 1 for two reasons. It is not stressed and it is of a shape not adapted to be wound compactly in a coil. To eliminate these disadvantages, the wire i further processed whereby it may be compactly wound as well as possessed of substantial internal stress in torsion.

For that purpose the storage reel 18 from the system of FIG. 5 after being filled, is transferred to a support element or bracket 19 (FIG. 7) mounted on a fixed bearing 20 capable of allowing the reel axis to be rotated in a plane generally normal to that of the wire and through the reel axis so that torsional stress applied to the wire 17a may enable the reel 18 to rotate about the axis of a spindle 21 by which the bracket 19 is connected with the bearing 20. The twisted unstressed wire 17a shown here as coming off the reel 18, is thus the same as that which is designated at 17 in FIG. 5 as being wound upon the reel 18. A first pair of straightening rolls 22 and 23 (FIG. 7) preferably are provided to pull the wire from the reel 18 and feed it toward a reel or mandrel 26 on which the wire, now torsionally stressed, is wound flatwise. A second pair of straightening rolls 24 and 25 rotate around the Wire in the plane of their axes to untWist the wire and apply torsional stress thereto in doing so. These may be located closely adjacent to the wind-up mandrel 16 and are preferably spaced apart from the first pair of straightening rolls 22 and 23 by an amount equal to at least a full twist thereby to permit the wire to become untwisted and thus to be restressed torsionally for winding fiat on the mandrel 26 without weakening any of the torsional stress. This restressing in torsion by untwisting the unstressed wire 17a is in value about half of the clastic limit of the tempered wire. This in pounds per square inch may exceed the stress imposed on the wire at 16 due to the higher elastic limit imparted to the wire at 17 following the heat treatment and quenching.

In FIG. 6 is shown a specimen of the wire 16 before being untwisted by the straightening rolls, 22 to 25 inclusive. In this figure of the drawing the degree of twist, is sufficient to have one full twist i.e. from a peak on one edge to a next peak on an opposite edge, of about 3 inches. This wire is about .025 inch thick and .25 inch wide.

After winding a desired length of wire upon the mandrel 26, the mandrel is removed from the wound wire and from the shaft 27. This mandrel is shown in FIG. 8 as being in four parts, or segments 49, 50, 51, and 52 mounted on the shaft 27, and capable of being slid longitudinally off this shaft. When these four segments are assembled on the shaft 27, an elastic band (not shown) or the like may be placed adjacent each end to hold these segments in place, such bands passing around a plurality of tying cords or straps 53 placed within corresponding longitudinal grooves illustrated. In starting to wind the torsionally stressed wire flatwise on the mandrel, one end is anchored by being given a short bend 40 and placed within a slot provided at one end of the mandrel as shown. When a desired length has been wound, the tie cords 53 at one end are each made fast to their opposite ends over the top of the wound wire to securely hold the torsionally stressed layers of wire against coming off accidentally. The four parts of the mandrel are then slid longitudinally off the shaft 27, leaving the coiled and stressed wire convolutions bound or held together for insertion into one end of the gun which comprises a cylindrical housing 29 as described below and shown in FIG. 2. The inner end 40 is placed in a notch 38 in a centrally-located rod or dart 34 before the coil is inserted into the housing 29. After being inserted into the housing the tie cords may be cut and pulled out longitudinally from around the coiled wire and the end of the housing.

The housing 29 is of tubular lightweight material, such as aluminum or plastic into an open end of which the bound coil convolutions may be slid. This end is closed by a suitable outer cap 30 clamped between two nuts 31 and 32 threaded on a central light metal guide tube 33 to which it is thus secured and in which is received the rear end of the dart or rod 34 and a firing pin 35. The firing pin 35 is releasably connected to the dart by suitable means such as an S-shaped interlock or joint 48 illustrated. With the arrangement, when the firing pin 35 is pulled back far enough, the right end becomes disconnected from the dart 34, allowing a small helical spring 36, compressed between the front end of the tube 33 and a head or forward end 37 of the dart, to be released thereby, ejecting the dart 34 forwardly from the gun. The notch 38 receives the inner end 40 of the torsionally stressed wire coil which thus moves out of the gun with the dart or rod 34 and the close-wound spring 36. With this connection, any notched rod may serve to carry the inner end 40 of the wire coil and the helical driving spring 36 closely surrounding said rod out of the housing and allow the stressed Wire to be relieved. As this occurs, the twist is resumed progressively, thereby forcing the wire forward as the stress in the wire becomes freed in successive convolutions. An inner housing wall 41 is of foam rubber or the like is provided with a central opening to assist in guiding the wire being ejected. This is preferably slightly larger than the dart 34 and its head 37. In the forward end of the housing 29 and beyond the wall 41 is a hollow cylindrical body 42 of material such as excelsior or sawdust or the like capable of exerting a slight retaining effect upon the wire coil convolutions, and to protect against coil damage under shocks in handling. A light cap 43 closes the front end of the housing and a pull-off type tape binding element or ring indicated at 44 holds the cap in place. The cap 43 is of light material adapted to be punctured by the dart in the event that it is not removed and has been forgotten when the device is put into use. A soft metal safety pin 45 of the general shape shown in FIG. 3 locks the pin 35 and the spring 36 against being compressed by pulling ring 46 until after this safety pin 45 has been removed from its cooperation with the groove illustrated in the firing pin 35.

In FIG. 4 is shown another type wire having barbs 47 formed by stamping along at least one edge of the Wire and for use in quickly laying barbed wire entanglements for their usual uses in impeding movements of personnel. In the embodiment of FIG. 4 the wire is about 0.24 inch thick, about .250 inch in width including the barbs, and is twisted, heated, treated, and untwisted in applying torsional stress thereto as described above.

The wire described when stressed during untwisting to only about half its elastic limit in torsion has been found to be capable of throwing the initially ejected end of the wire a distance of 100 feet or more at a rate of about 100 feet per second. After removal of the safety pin 45 and pulling the ring 46 away from the operators other hand holding the housing 29, the dart is ejected and starts ejection of the wire. The dart, or other rod used in its place falls in a few feet while the wire continues to retwist and expand forwardly. Thus it may be used for throwing a communication wire or a wire for initially pulling a heavier wire across a chasm or depression as shown in FIG. 1. Where the ground is flat this invention is useful in quickly laying a message wire. Such a wire should be insulated with a layer only about .001 of an inch thick of a well plasticized plastic or an enamel applied after heat treatment and before winding on the mandrel.

Among the advantages of this gun in use may be mentioned the ability to quickly and easily lay wire entanglements and wire for communications with a range of 100 feet or more with a velocity of to feet per second. These values are not believed to be upper limits because thicker wire should enable greater ejecting force to be available. Any shape of wire cross section may be used but a flat wire or a wire of rectangular cross section has the advantage of showing the degree of its permanent set when twisted and when untwisted enables the wire to be compactly wound for storage, ready for use as a wire gun or for many other purposes. The housing is light in weight, as is desirable. As a dispenser of wire entanglement this wire gun is said to have a psychlogical effect upon impact of the leading inner end of the wire a coil upon personnel. Where bar-bed wire has heretofore been used to obstruct approach troops, this improvement may be caused to surround and attach to moving troops. The

outer end of the torsionally stressed wire coil needs no special holding as does the inner end of the coil but will be adequately secured when the coil snugly slides into the housing 29. The degree of Rockwell C hardness after tempering determines an elastic limit much more than double the wire strength when soft and before tempering. Space economy in winding the stressed wire flatwise is an important feature of this invention.

It is obvious from the foregoing description that a plurality of wires may be simultaneously ejected from a plurality of windings. Likewise, as described for one wire, a plurality of wires may be simultaneously wound and ejected from the same coil simultaneously with the wires nested.

I claim:

1. A wire gun comprising a light weight tubular housing, a coil of spring wire having internal stress in torsion below its elastic limit, said coil being held within said housing and having a generally hollow core with a plurality of concentric layers extending from an inner layer and end at said core to an outer layer and end therein, means for holding the inner and outer ends of said coil secured against becoming unwound, and means for ejecting the inner end of the coil through said core and externally of the housing to release said torsional stress and extend the wire substantially its full length.

2. A wire gun and coil spring combination according to claim 1, in which a releasable compression spring engages said housing and the inner end of said wire coil within the core thereof as part of the means for ejecting the inner end of said coil.

3. A wire gun and coil spring combination according to claim 1, in which the spring wire of the coil has two edges, and in which a plurality of barbs are provided along at least one edge of said spring wire.

4. A wire gun and coil spring combination according to claim 1, in which the coil convolutions are flat and lie with their flat side touching a radially contiguous layer of convolutions.

5. A wire gun and coil spring combination according to claim 1, in which a generally axial dart has a notch element with an inner end of said wire coil received therein for release as part of said ejector means.

6. A wire gun and coil spring combination according to claim 1, in which said spring wire is of tempered steel having a yield strength at least double that of the steel in soft and untempered condition.

7. A wire gun comprising:

(a) a multi-layered helically-wrapped coil of wire, said wire in said coil being elastically twisted longitudinaly throughout its length to a point approaching but not exceeding its yield point,

(b) a canister open at one end and surrounding said coil,

(c) a restraining device within said canister releasably holding the end portion of the innermost layer of said wire, and

(d) selectively operable triggering means exposed on the exterior of said canister and extending therewithin into operative engagement with said restraining device for selectively releasing the hold of said device on the wire on said coil, whereby upon actuation of said triggering means said wire is released and self-discharges substantially linearly outwardly under the cumulative impulse of its own released elastic energy through the open end of said canister.

8. A wire gun comprising:

a multi-layered helical coil of tempered and hardened spring wire having a cross-section adapted to lie flat and closely compact in the coil layers,

said wire in said coil being untwisted longitudinally throughout its length under torsional stress below its elastic limit from a set longitudinal twist throughout its length above its elastic limit,

a cylindrical housing for said coil having a closed rea end and an extended forward end with a central guide opening therethrough for ejecting said wire,

a restraining device within the housing releasably holding the end portion of the innermost layer of said coil, and

movable triggering means for said restraining device having an external operating element extending internally into connection therewith for releasing said wire end and the coil progressively discharged outwardly through said guide opening and extend forwardly full length into a retwisted torsionally unstressed form.

References Cited UNITED STATES PATENTS 2,370,036 2/1945 Howell 8936 2,654,321 10/ 1953 Robinson l0263 2,908,484 10/1959 Uhl 256-8 1,934,122 11/1933 Hill 15378 2,289,398 7/1942 Whist 15378 1,486,807 3/1924 Skala l2426 1,673,945 6/ 1928 Littlefield l2426 275,282 4/1883 Stanton et al. 46-146 X 3,181,524 5/1965 Bratz 124--16 ANTON o. OECHSLE, Primary Examiner MAX R. PAGE, Assistant Examiner US. Cl. X.R. 

1. A WIRE GUN COMPRISING A LIGHT WEIGHT TUBULAR HOUSING, A COIL OF SPRING WIRE HAVING INTERNAL STRESS IN TORSION BELOW ITS ELASTIC LIMIT, SAID COIL BEING HELD WITHIN SAID HOUSING AND HAVING A GENERALLY HOLLOW CORE WITH A PLURALITY OF CONCENTRIC LAYERS EXTENDING FROM AN INNER LAYER AND END AT SAID CORE TO AN OUTER LAYER AND END THEREIN, MEANS FOR HOLDING THE INNER AND OUTER ENDS OF SAID COIL SECURED AGAINST BECOMING UNWOUNDS, AND MEANS FOR EJECTING THE INNER END OF THE COIL THROUGH SAID CORE AND EXTERNALLY OF THE HOUSING TO RELEASE SAID TORSIONAL STRESS AND EXTEND THE WIRE SUBSTANTIALLY ITS FULL LENGTH. 